This invention relates generally to means for repairing pipe line leaks and, more particularly to a leak repair clamp for sealing leaking flange pipe couplings, valve bonnet flanges, or leaks through the exterior of a pipe section wall.
Flanged pipe couplings are widely used for connecting together sections of pipe in larger sizes and operating in moderate to high pressures. Various configurations of seals are utilized between the flanges, but one of the most common forms is to provide a raised face on the inner portion of each of the flange faces between which an annular gasket is placed, and, when the flanges are bolted together, the raised faces plus the gasket material tighten between them to form a seal.
However, such flange pipe couplings may often begin to leak, because of deterioration of the gasket material or shifting of the pipe, or for other reasons. Similarly, a leak may occur in the outer wall of a pipe section due to a defect in the manufacture of the pipe, or because of damage to the pipe during or after installation. Such leaks must be repaired, and often in the past the pipe line had to be shut down and drained of its contents before such a leak could be repaired. The prior art shows pipe flange repair clamps, such as those disclosed in U.S. Pat. Nos. 866,395 and 3,152,816, for sealing the leak between pipe flanges. However, these flange repair clamps are extremely complex and have a number of movable and adjustable parts that make the clamp expensive and difficult to utilize.
To repair leaks in pipe lines or around weld joints, outer sleeves that are specially made and custom fitted to the particular pipe line have been used. They are set over the leak, clamped or welded together, and then the interior of the sleeves has been filled with a sealant material. However, the custom making of such sleeves is extremely expensive, and their attachment to pipe sections is time consuming, tedious and expensive.
Accordingly, one primary feature of the present invention is to provide a repair clamp for pipe and pipe flanges and the like that utilizes a self-energizing seal to speed the leak repair action.
Another feature of the present invention is to provide a simple clamp that can be utilized with minor modifications, both for sealing leaks in pipe lines or pipe line sections and pipe flanges.
Yet another feature of the present invention is to provide a leak repair clamp that utilizes a compression seal that can be self-energizing, used in high temperatures, and in applications where the product leaking from the pipe line or flange is corrosive.